Re: xargs prompts with the same string, but executes differently

[Assaf Gordon]

Hello,

On 2019-07-23 9:59 a.m., 積丹尼 Dan Jacobson wrote:
> Proof that xargs prompts with the same string, but executes differently:
>
> $ echo 0 0 | xargs -p -I{} xdotool mousemove {} click 1 mousemove restore
> xdotool mousemove 0 0 click 1 mousemove restore ?...y
> xdotool: Unknown command: 1
> Run 'xdotool help' if you want a command list

> $ echo | xargs -p xdotool mousemove 0 0 click 1 mousemove restore
> xdotool mousemove 0 0 click 1 mousemove restore ?...y
> $ xargs --version
> xargs (GNU findutils) 4.6.0.235-f254 ...

This is not about "-p", but simply that "{}" puts the entire input line
("0 0") as a single parameter (as if quoted).

The correct comparison is:

  echo | xargs -p xdotool mousemove 0 0 click 1 mousemove restore
vs
  echo | xargs -p xdotool mousemove "0 0" click 1 mousemove restore

The following short script will help you investigate such cases in
the future:

  $ cat show-args
  #!/bin/sh
  i=1
  while test $# -gt 0 ; do
     echo arg $i:  $1
     shift
     i=$((i+1))
  done


  $ echo 0 0 | xargs -I{} ./show-args xdotool mousemove {} click 1 
mousemove restore
  arg 1: xdotool
  arg 2: mousemove
  arg 3: 0 0
  arg 4: click
  arg 5: 1
  arg 6: mousemove
  arg 7: restore

  $ echo | xargs ./show-args xdotool mousemove 0 0 click 1 mousemove 
restore
  arg 1: xdotool
  arg 2: mousemove
  arg 3: 0
  arg 4: 0
  arg 5: click
  arg 6: 1
  arg 7: mousemove
  arg 8: restore



regards,
 - assaf